Perhaps you should try some spelling variations:
van thanh » ban thanh
cua triet » cua viet, su triet, va triet
van tuan » van quan, van ban, anh tuan
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
ve cac » va cac, vien cac
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang xa hoi. hieu ((he bac) or (ve cac)) bo ((van thanh) OR (van tuan)) vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu ((he bac) OR (ve cac)) bo ((van thanh) OR (van tuan)) vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu ((he bac) or (ve cac)) bo ((van thanh) OR (van tuan)) vi cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu ((he bac) or (ve cac)) bo ((van thanh) OR (van tuan)) vi cua triet*.